Mildewproof fabric and process of making same



Patented Oct. 13, 1931 UNITED STATES PATENT OFFICE RAYMOND HARVEY, OF NEW YORK, N. Y., AND HARRY V. DAY, OF PEQUANNOCK TOWN- SHIP, MORRIS COUNTY, NEW JERSEY, ASBIGNORS TO THE PANTASOTE LEATHER COMPANY, OF PASSAIC, NEW JERSEY, ACORPORATION O F NEW JERSEY mnmnwrnoor FABRIC AND No Drawing.

mildewproofed making same,

and more articularly to the method of milg a heavy fabric such as duck, coated with a colored pyroxylin dope in such a manner that a pliable fabric highly resistant to mildew fungi and spores, and also highly water-resistant, and of pleasing appearance, is produced.

One of the most important problems faced by manufacturers of articles composed of or covered with fabric material designed to be used in'locations where they are exposed to atmospheric conditions--for example awnings, and the like-is the tendency of such fabrics-to mildew, which spoils their appearance and rots their substance. Numerous attempts have been made to overcome this difliculty by treating such fabric with various chemicals, but such treatment has heretofore failed to impart the desired mildewproofing character to the fabric, and in certain instances has considerably impaired the appzarance'and pliability of the same. It has en found that where the fabric is coated with an oil-containing varnish or paint the coating itself is attacked by mildew, the tendency to mildew increasing with increase in an oil, such as castor oil, is added to the nitrod oleates, palmltates, stearates and resmates of than offset, by a was found to the amount of oil in such coating. This property of oil-containing coatings is strongly in evidence in the case of fabrics covered with a layer of pyroxylin dope or lacquer wherein cellulose base to increase the flexibility an pliability of the coating. An increase in t e oil content of the dope for the urpose of increasing the pliability of the nished fabric accompanied by a decrease in the resistance of such fabric to mildew, so that a gain on the one side was offset, or more loss on the other.' All atts heretofore made to increase the milof fabrics to our knowledge have been accompanied by a decrease in the flexibility or liability of the finished product, or by a oss inthe appearance of such product, or both. o

It is an object of the presentinvention so to I treat fabrics that they are made substantially resistant to mildew, while at the same time temp dew resistance raocnss or MAKING sum Application filed November 21, 1928. Serial No. 321,032.

their appearance and pliability are not only not impaired, but are even improved.

In accordance with our invention the fabric to bemildewproofed may be first treated with a suitable chemical to render the same proof against mildew and is then treated with a pyroxylin dope within which may be suspended or dissolved'a pigment or other coloring matter. The dope is coated or read on the fabric preferably by means of a ife.

e pyroxylin dope may or may not contain a mildewproofing chemical which is compatible with the pyroxylin and with the solvent thereof. ere a mildewproofing agent is used in the dope, the latter may contain a high percentage of extremely flexible Without increasing the tendency of the coating to m'ldew, We have oil to render the coating found that such extremely pliable coatings,

tate, lead oleate, the salts of the rare earths or mixtures thereof, such as are obtained from monazite sand, etc. The mildew-proofmg materials em loyedwith the dope with which the fabric is coated may comprise t e aluminum, zinc, lead, calcium, etc; and, 1n general, the insoluble metallic 'soaps or mixtures thereof, zinc resinate being particularly suited to our pur ose. We have found that essential oils are a so proofing agents. The plasticizer for the pyroxylin .dope may be any known lasticizer, such as tricresyl phosphate, a vegetable oil such as castor oil, etc. The dope is preferably spread on the fabric by means of a octor blade; the fabric thus becomes coated in such manner that the hollows of the fab or the spaces between the yarn, are filled with the dope while the raised portions of the fabric, or the yarns themselves receive only a light coating, thereby producing a applicable as mildewric,

pleasing pebble efiect. The coating so produced has also a highly desirable gloss or sheen, in contradistinction to the coating produced by painting or printing with oxidizing oil paints or inks, such as linseed oil paints, Whose coatings lack flexibility andpliancy and are dull 1n appearance and harsh to the touch.

In carrying out our invention we may coat w a fabric, preferably of a rather heavy'texture, I such as duck, directly with the pyroxylin dope described below, or we may first impregnate such fabric in a vat or between rolls or in a w jig with a solution of a mildew-proofing water-insoluble metallic soap such as lead oleate etc. or mixtures thereof, in a suitable solvent. The fabric is then dried to remove the solvent. If the fabric has been treated with a solution of aluminum acetate in water, the, drying operates to render the salt insolublein water. The fabric. whether it has been so pro-treated or not. is then coated with a pyroxvlin dope containing, for example, the

ollowing ingredients:

12 lbs. pyroxylin (dry weight) 55 s. blown or processed castor oil (which has been heated) 5 lbs. zinc resinate -85 lbs. pigment 90 lbs. (approximately) solvent The dope is prepared by first dissolving the pyrcxylin in the solvent, which may be composed of by weight of ethyl acetate,

til-

% benzol and 25% alcohol. The zinc resihate or other suitable metallic soap is dis solved in the castor if necessary, after which the pigment is ground with same therein in a fine state of division. The pyroxylin solution and the oil mixture are then mixed together, and the fabric coated with the resulting mixture by means of a doctor blade, which operates to spread the dope thereon. This solution may be applied to both sides of the fabric or else, as stated above. the opposite sides of the fabric may be dil) pigments so as to obtain two color eects.

It will be found that fabrics treated as.

above described, even when coated on both sides thereof, are extremely pliable, have a pleasing glossy and pebbly edect, and are soft to the touch. A fabric produced in accordance with our process is stable against atmospheric conditions, is substantially mildew-proof, and is not liable to rot as are fabagent, for example aluminum acetate or a such oil solution to suspend the coated with mixtures containing difierent naaaoea W e claim 1. The method which comprises impregnating a fabric with a mildew-proofing a ent and spreading a. coating of pyroxylin ope thereon containing a plasticizer and zinc resinate.

2. The method which comprises coating a fabric with a pyroxylin dope containing Z1110 resinate.

3. A mildewresistant material comprising a fabric impregnated with'aluminum acetate, and coated'on at least one side with a pyroxylin lacquer containing a plasticizer and zinc resinate.

4. A mildew-resistant material com rising a fabric coated on at least one side with a pyroxylin lacquer containing a plasticizer and zinc resinate.

RAYMOND HARVEY. HRY V. DAY.

oil. heat being employed lllll lid 

